The federal government has slapped multimillion-dollar fines on companies that market four types of weight-control compounds. Not because the pills are unsafe, but because regulators decided the companies' claims about their products' results were false.

People throughout the world spend billions of dollars a year on weight loss pills.

The U.S. government says some of these pills -- including Xenadrine EFX, CortiSlim, TrimSpa and One-a-Day WeightSmart, do not live up to advertising claims.

Deborah Platt Majoras, from the U.S. Federal Trade Commission, says the loss to the consumer is not weight. "Paying for fad science and miracle ingredients is a good way to lose nothing but your cash."

The Federal Trade Commissionsays claims by the makers of these products are not backed by science. The Commission says celebrity endorsements and other advertising make losing weight seem easy.

The marketers have to pay hefty fines. The companies have also agreed to change their ads, although Bayer, which makes WeightSmart, and TrimSpa say scientific research does back their product claims. People will still be able to buy these products because they are not considered harmful.

The products are also available outside the United States.

But weight-loss expert Dr. Louis Aronne hopes consumers will be more aware. "My hope is that what will come from this is that consumers will be more aware and more skeptical of these products, that businesses won't carry them."